Wire fabric



Aug. 15, 1944. w. 1'; ENNOR 2,355,963

WIRE FABRIC Original Filed Ju1y l6, 1940 INVENTOR WILLIAM 1". ENNOH BY ATTORNEY Patented Aug. 15, 1944 lem has of the wires of UNITED STATES PATENT OFFICE wrap memo WilllamTreh ane Ennor,

to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Continuation of application Serial No. 345,818,

July 16, fierial No. 535,821

A 12 Claims.

' Because of aluminums light weight, durabil ity, attractive appearance, and non-staining characteristics; attempts have been made to make wire fabric from it and its alloys for use as screen cloth and the like. However, difllculty has been encountered in producing aluminum wire fabric which is suitable for commercial purposes. One of the principal difflculties has been that the fabric was sleazy? and not stifl enough. The terni "sleazy refers to susceptibility of the fabric to be manipulated easily intoa conditionwhere the wires do not cross at right angles. Another probbeen to produce fabric which was sufilciently resistant to corrosion.

when, in order to obtain increased corrosion resistance and other deslred properties, aluminum wire fabric' is made from duplex wires consisting of a core of an aluminum basealloy enclosed in a coating of a softer alloy of a higher electrode potential than the core, the fabric is ordinarily extremely stiff, in contrast to the'sleazy condition mentioned above. The fabric also frequently possesses a ridged or uneven appearance, andthe Weft wires may be unevenly spaced as a result of what is generally known in the wire fabric industry as flyback."

It is an object of this invention to provide an improved aluminum wire fabric. It is a further object of this invention to provide an improved. aluminum wire fabric made from duplex wires Newark, Ohio, assignor 1940. Thisapplication May 16, 1944,

- wires is harder than the coating" of the weft or filler wires, the degree of stiffness of the cloth is less than it would be if the coating metal on both setsofwires were of equal hardness, and

furthermore,- any tendency toward uneven spacing of the weft wires and toward the formation ofridges or bulges in the cloth during the weaving of it is'minlmized.

It is preferred to make the ,warp and weft wires from duplex wire having a core of a suitimprovement in tensile of the type mentioned above, which is neither too stiff nor too sleazy, and which is free from bulges and ridges and-uneven spacing of the weft wires resulting from flyback. It is a further object of this invention to provide aluminum wire fabric woven from duplex wires having an aluminum base alloy core and an aluminum base alloy'coa'ting around the core, the coating alloy of certain the fabric having mechanical properties differing from those of the. coating of the other wires in the fabric.

- Referring to the accompanying drawing,

Fig. 1 is an elevation of wire fabric embodying myinvention; and

Fig. 2 is an enlarged cross-section taken on the line IIII of Fig. 1.

. My invention is predicated upon the discovery 4 that when aluminum wire fabric is made from able aluminum base alloy and a coating of another aluminum base alloy, the latter alloy being susceptible to having its mechanical properties changed by proper treatment. The wire which is to form the warp wires of the fabric, or that which is to form the weft wires, or both, can. then be subjected to suitable treatments for producing warp and weft wires in which the surface of the warp wires is harder than the surface of theweft wires. p

Many aluminum base alloys are susceptible to strength, yield strength, and hardness by certain thermal treatments whichcause'soluble alloying elements to enter into solution in the aluminum base metal. Those elements can be retained in solution by a rapid or controlled cooling from the elevated temperature of the thermal treatment to room temperaa cooling step.

tu're, even though their solubility in the aluminum is actually lower at room temperature than the amount retained in solution after the ment is known to those skilled in the art as a so lution heat treatmen and the alloyswhose mechanical properties can be substantially improved by such thermal treatments are referred to as heat treatable alloys. Generally speak-- ing,-the preferred solution heat treatment temperature varies with the condition and character of the alloy, but a-range of between 400 C. and

550 C. includes practically all of the commercial solution heat treatments-for aluminum base alloys.

In the preferred form of my invention the wire The elevated temperature treat of a coreof a strong aluminum base alloy which is a not susceptible to having its mechanical properand that portion of the wire which is to form the weft wires is annealed, thereby softening the coating alloy on it. The wires normally are subjected to a final drawing operation to draw them to final size subsequent to th thermal treat ments mentioned, and although the drawing operation results in substantial changes in the mechanical properties of the wire because of the working of the metal, the wires still show marked differences in surface hardness resulting from the thermal treatments described previously. A reduction of from '75 to 96 per cent in the cross- ,sectional area of the wire is desirable during this drawing operation. Following the final drawing operation on the warp wire it is preferred to subject it to an artificiah'aging treatment, which consists of heating the wire at a temperature between 100, C. and 200 C. This-treatment increases the hardness of the coating alloy, and in addition, when the alloy forming the core contains magnesium, the ductility and percent. age of elongation of the wire is increased, with the result that breakage of the wire during weaving is minimized. Ordinarily a treatment for about four hours at 118 C. is satisfactory for this step. The artificial aging treatment may pre-- cede the final drawing operation on the warp wire, but preferably follows the drawing operation.

The duplex wire giving the best results is that consisting Of. a core of an aluminum base alloy containing from 3-6 per cent magnesium, from 0.05-1 per cent manganese, and from 0.05-0.5' per cent-chromium, the balance being aluminum plus impurities, which core has a coating of an aluminum base alloy containing from 0.5-3

per cent zinc, from 0.75-3 per cent magnesium silicide, and either from 0.05-.5 per cent chromi um or from 0.1'-1 per cent manganese, the bal-' body of wire being treated.

a solution heat treatment at a temperature of I 2,855,968 fabric is made from aluminum wire consisting the thermal treatments described above, and the duration of the thermal treatments, varies, de-

pending on such factors as the particular composition and size of the wire and the size of the For most purposes 510 C. is satisfactory, and an anneal at 350C. is adequate for the annealing treatment. After the solution heat treatment, th warp wire may be quenched from the. solution heat treatment temperature by immersing it in water or oil, or

v by passing a current of air over it, in the manner ance being aluminum plus incidentalimpuiaties. With wireof'the above described COmPOSitiOQRhG hardness of the coating can be increased by 9.

properties of the core are not substantially increased by the solution heat treatment.- Prior to weaving the fabric, the wire-which is to form the warpwires is subjected to a solution heat treatment by heating it at a temperature of about 510 0., as described in U. S. Patent 1,472-

739 to Archer et al. The wire which is to form et al., with the result that the hardness of the the result that the coating on coatingt and the ductility and percentage of elongation of the core, are increased.

The particular temperatures most suitable for weft wires.

well known in the art. Fabric woven from wires prepared in the manner described above is free from ridges or bulges, and has, a degree of stifiness satisfactory for commercial purposes. Furthermore, the solution heat treated wires have a relatively hard surface, and consequently do not tend to become scratched during the weaving of the fabric, with the result that the wire has a smooth appearance. No rolling or other treatment of the woven fabric is necessary to prepare it for commercial use, but if desired, the fabric may be painted with aluminum paint or other types of paint.

Though the above described procedure for obtaining a difference in surface hardness of the warp and. weft wires is preferred, various other known methods for achieving the difference in hardness may be employed. For example, both the warp and weft wires can be annealed to the same extent, so that their properties are similar, and then be subjected to a final drawing operation in which the weft Wire is drawn to a lesser amount than the warp wire. weft wire is work-hardened by the drawing operation to a less extent than thewarp wire, and consequently the coating on the warp wire is harder than the coating on the weft wire. To produce warp and weft wires of like cross-sectional dimensions and of differing hardness in this mannor, the wires must be drawn prior to annealingv to suitably differing cross-sectional dimensions to compensate. for the difference in reduction in the final draw. Another used to obtain a difference in the properties of the two sets of wire is to soften the weft wire by annealing it following the final drawing oi eration, but, not annealing the warp wire, with the result that the warp wire remains in the work-hardened condition.

In the accompanying drawing of wire fabric the warp wires I and the weft wires 2.- The warp and weft wires consist of a core 3, which is composed of an aluminum base alloy, and a coating I of a different aluminum base alloy which has a higherelectrode potential than the core. The warp and weft wires have been treated as described above prior to weaving the fabric, with I V the warp wires is substantially harder than the coating on the As a specific example of my invention, wire fabric was made of duplex wire composed of a core ving a composition of 0.1 per cent manganese, 5.25 per cent magnesium, 0.1 pe.r cent chromium, and the balance aluminum plus incidental impurities. The coating on the core consisted of an alloy having a composition of 0.25 per cent chromium, 2 per cent zinc, 1.9 per, cent magne slum silicide, and the balance aluminum plus impurities. That portion of f'the wire which was to form. the warp wires of As a result the method which can be.

solution heat treatment. while the mechanical odying my invention. he fa ri c nsis s f 5 the fabric was given a fassacos inch to .015 of an inch, and thereafter was heated for four hours at a temperature of 118 C. The

fabric was annealed by heating it at a temperature of 350 C. After it had cooled, it was subjected to a final drawing operation, similarto that'which was given the warp wire, reducing the diameter of the wire from .064 of an inch to .015 of an inch. The two sets of wire were then woven into wire fabric, and that fabric was fiat and uniform in appearance, and was neither too stiff nor too sleazy for commercial use.

If a combination of duplex wires is used in which the surface of the weft wire is harder than the -surface of. the warp wire, the stiffness of the fabric is greater than isthe case when the warp and weft wires are of equal hardness. Although ordinarily the problem with fabric made of duplex aluminum wires is to decrease v the stiffness, it is sometimes advantageous to obtain an increase in stiffness, as where the fabric is made from wire ofextremely small diameter or there is a large distance between the wires. In such case it is desirable to increase the stiffness of the fabric, and this may be accomplished by weaving the fabric from wire in which the surface of the weft wires is harder than the surface of the warp wires. The difference in surface hardness can, of course, be obtained by the methods described previously, but in this case the process for increasing the surface hardness of the duplex wire is applied to the weft wire and the process for softening the surface is used on the warp wire.

I claim:

1. Wire fabric comprising warp -wires and 'weft wires, said wires comprising an aluminum base alloy core having a coating of a diiferent aluminum base alloy, the coating on one set of wires being of different hardness than the underlying core, and the coating on the warp wires being of different hardness than the coating on the weft wires. f

2. Wire fabric comprising warp wires and weft wires, said wires comprising an aluminum base alloy core having a coating of a different aluminum base alloy, the coating on the warp wires being of different hardness than the underlying core and harder than the coating t-onthe weft wires.

3. Wire fabric comprising warp wires and weft wires, said wires comprising. an aluminum base alloy corehaving a coating of a different aluminum base alloy, the coating on the warp wires being softer than the coating on the weft wires, and the coating on the weft wires having adifferent hardness than the underlying core.

4. Wire fabric comprising warp wires and weft wires, said wires comprising a core of a nonheat treatable aluminum base alloy having a coating of a heat -treatable aluminum basealloy thereon, one of said sets of wires having a solution heat treated coating of different hardness than the underlying core, and the other set of wires being in the softened condition resulting from annealing thereof.

. 5. Wire fabric comprising war-p wires and weft wires, said wires comprising a core composed of an aluminum base alloy having a. coating thereon --of a heat treatable aluminum base alloy, one of said sets of wires having a solution heat treated coating, and the coating on the other set of wires vbeing in the softened condition resulting from wire which was toform the weft wires of the Y annealing thereof, the core of the wire having the solution heat treated coating being of different hardness than the solution heat treated coating.

6. Wire fabric comprising warp weft wires, said wires comprising a core of a nonheat treatable aluminum base alloy having a coating of a heat treatable aluminum base alloy thereon, the coating of one of said sets of wires coating of one of said sets of wire being in the being in the solution heat treated and subsequently drawn condition, and the coating of the other set of wires being in the condition resulting from the-wire being annealed to soften it and then wire-drawn, said first mentioned coating being harder in the drawn condition than said second mentioned coating.

7. Wire fabriccomprising warp and weft wires, said wires comprising a core composed of an aluminumbase alloy having a coating thereon of a heat treatable aluminum base alloy; the

solution heat treated and subsequently drawn condition, and the coating of the other set of wires being in the condition resulting from the wire being annealed to soften it and then wiredrawn, said first mentioned coating being of different hardness than the underlying core and harder than said second mentioned coating.

8. In the method of making aluminum wire fabric in which the warp wires and weft wires comprise an aluminum base alloy core having a coating of a heat treatable aluminum base alloy,

the steps comprising subjecting the wire for one of saidsets' of wires to a solution heat treatment and subsequently subjecting it to a wire-drawquently subjecting it to a wire-drawing operation, whereby the coating of one of said sets of wires differs in hardness from the coating of the other set, and thereafter weaving wire fabric from the wires.

9. In the method of making aluminum wire fabric in which the warp wires and weft wires comprise an aluminum base alloy core having a coating of a heat treatable aluminum base alloy.

the steps comprising subjecting wire which is to form warp wires of the fabric to a solution heat treatment and subsequently subjecting it to a wire-drawing operation, the coating alloy of the resultant material being of different hardness than the 'core, subjecting the wire which is to form weft wires of the fabric to an annealing treatment, whereby the coating alloy thereof issoftened, and subsequently subjecting it to a wiredrawing operation, whereby the coating of one set of wires differs inhardness fromthe coating of the other set, and thereafter weaving wire fabric from the wires.

10. In the method of making aluminum wire fabric in which. the warp wires andweft wires comprise an aluminum base alloy core having a coating of a heat treatable aluminum base alloy, the steps comprising subjecting the wire' for one of said sets of wire to a solution heat treatment, thereafter subjecting it to a wire-drawing operation, and subsequently heating it at a temperature of from to 200 C., the coating alloy of the resultant material being of difierent hardness wires and e than the core, subjecting the wire for the other of said sets of wire to an annealing treatment, whereby the coating alloy thereof is softened, and subsequently subjecting it to a wire-drawing operation, whereby the coating of one of said sets of wires differs in hardness from thecoating of the other set, and thereafter weaving wire fabric from the wires.

11. In the method of making aluminum wire fabric in which the warp wires and weft wires comprise an aluminum base alloy core having a coating of a heat treatable aluminum base alloy,

the steps comprising subjecting the wire which warp wire is harder than the coating of the weft wire, and thereafter weaving wire fabric from the wires. I

12. In the method of making aluminum wire fabric in which the warp wires and weft wires comprise a non-heat treatable aluminum base alloy core having a coating of a heat treatable aluminum base alloy, the steps comprising subjecting the wire for one of said sets of wire to a solution heat treatment, subsequently subjecting it to a wire-drawing operation, and thereafter heating it at a temperature of from 100 to 200 C., the coating alloy of the resultant material being of different hardness than the core, subjecting the wire for the other of said sets of wire to an annealing treatment, whereby the coating alloy thereof is softened, and subsequently subjecting it to a wire-drawing operation, whereby the coating of one of said sets of wire difiers in hardness from the coating of. the other set, and thereafter weaving Wire fabric from the wires.

WILLIAM TREHANE ENNQR. 

